The present invention relates to photometrically monitoring and supervising the emission of dust, and more particulary, the invention relates to calibration of such a photometric process.
The production of dust in processes which are prone to produce dust is usually monitored, possibly quite extensively. For example, blower converters produce a smoke filled gas blast which is wet dedusted or scrubbed before discharge into the outer atmosphere and the discharge flow is monitored as to the dust content. The instrument undertaking the supervision must be frequently recalibrated. For this, automatic calibration equipment is activated intermittently in regular intervals, e.g. in one hour intervals the monitoring equipment is disabled to undergo calibration for about a minute.
During the calibration period measuring data are not available. It was found that this temporary deactivation of the dust monitoring equipment is not acceptable as quite frequently valuable data are lost.